Apparatus for gunfire control



w. w. WILLARD ET AL APPARATUS FOR G UNFLRE CONTROL Filed Feb. 21, 1955 Com a-u'azzanz Execufrix of Esrofe of Flu-W Waldo w. wiama, and

THEIR ATTORNEY Patented July 15, 1947 UNITED STATES PATENT OFFICE APPARATUS FOR GUNFIRE CONTROL tion of New York Application February 21, 1935, Serial No. 7502 This invention relates to apparatus for compensating for errors in the aiming of ordnance mounted on angularly movable platforms, such as ships.

The angular motions of a ship referred to herein are those relative to a horizontal datum plane as distinguished from the angular motion, commonly known as yaw, which takes place in a horizontal plane. The term roll is employed to designate the movement of the ship about a fore and aft axis. The term pitch is employed to designate the movement of the ship about an axis lying at right angles to the fore and aft axis, that is, a movement about an athwartships axis. The terms level and cross level are used in general to designate the displacement of the deck from the horizontal measured respectively about an axis perpendicular to the line of sight and about an axis perpendicular to the first axis. Thus either or both of the axes about which level and cross level are measured may be maintained horizontal or may approximate the horizontal, for example, being constrained parallel to the deck. For the purpose of this disclosure level is measured about an axis parallel with the deck and the cross level axis is horizontal when the roll equals a predetermined selected value in accordance with this invention. The selection of the particular axis depends upon the form of director sight Or other factors of the problem. The sidewise positioning of the gun from the vertical plane containing the line of sight to compensate fo the effect of the wind, drift of the projectile, travel of the target during the flight of the projectile, etc., is known as lateral deflection, or sight deflection.

Assuming, as a convenient example, that the lateral deflection is zero, 1. e., that the line of fire is lying in the vertical plane of the line of sight, so that a gun is lying with its bore axis substantially in that plane, the effect of the cross level is to cause a proportional tilt of the trunnions of the gun relative to the horizontal plane. This trunnion tilt in connection with the elevation of the gun for the range of the target causes a displacement of the bore axis of the gun from the position it should occupy in order that the gun may be properly aimed. This displacement of the gun causes errors in both train and elevation which must be corrected if the gun is to be properly aimed. The error in train is relatively large as compared to the error in elevation. Since the error in train depends upon the tangent of the angle of gun elevation, this error increases rapidly as the elevation of the gun is increased for long ranges.

Moreover, the required training movements are, for many conditions of operation under previous methods, in excess of those which the guns or their turrets are capable of properly following.

6 Claims. (CI. 8941) Heretofore it has been customary to continuously determine and apply to the gun the required corrections in train and elevation in accordance with the varying values of cross level. In the case of large caliber guns which are normally fired at relatively high angles of elevation, considerable difiiculty has also been experienced in causing them to rapidly and accurately execute the required movements in train which they must do if the guns are to be continuously properly aimed.

This invention has for its general object the provision of an apparatus fo compensating for the errors caused by cross level, which functions so as to avoid the above mentioned difficulties, particularly in the case of large caliber guns set at high elevation angles.

In general, the mode of operation of the ap-' ing of a target. The corrections required to compensate for the cross level errors caused by the selected roll and the varying pitch of the ship will be determined and applied to the gun which is fired at the instant when the selected roll exists. imum variation in train required to compensate for trunnion tilt is that due to the pitch of the ship. Since the roll of a ship is usually three or four times the magnitude of the pitch, the maximumtraining movement of the gun will be reduced to one-third or one-fourth of that required in the case of the usual method of compensating for errors due to the cross level.

One form of suitable apparatus for carrying out the invention is herein illustrated and will be hereinafter described. The particular nature of the invention, as well as other objects and advantages thereof, will appear most clearly from a. description of the particular apparatus illustrated in the drawing which is of a schematic nature for the sake of simplicity.

In the drawin l designates generally a sighting device or director as it is usually called. This device includes a pedestal 2 attached'to a'shipand provided with an annular gear 3 fixed theretof Within which is rotatably mounted a table 4. The

table carries a pair of standards 5 having bearingsv at their ends for shafts 6 supporting a telescope I for movement in a plane perpendicular to the table. The table also carries coupled hand-wheels 8 of the usual construction in instrument of this nature, and one of which is provided with a firing key 9.

Shafting I0 is geared to and leads from the hand-wheels through an aperture H at the cen- As a result of this arrangement the max-' 7 so designedas to permit. relative motion between the parts mounted upon the rotatable table 4 and the parts mounted upon the fixed pedestal 2 and leading to other elements of the apparatus which bear a fixed relation to the pedestal, without interfering with the transmission of .movement from the former parts to the latter parts due to operation of the hand-wheel.

Shaiting ported by a bracket l4 attached to the table 4.

supported in bearings 46 at the top of standards.

41 attached to the ship on a lineperpendicular to I that connecting the standard 43, so that the i3 is operatively connected to the I shafting l3 near the hand-wheels 8 and issup- The shafting i3 carries a pinion|5 meshing with the annular gear 3 so that operation of the handwheels causes the table 4 and the device mounted thereon to turn in train.

Anauxiliary telescope I3 is supported by a shaft i7 'passin through bearings at the upper ends of standards It afiixed to the ship parallel to of the telescope is athwartships or in the plane of the roll of the ship.

Coupled hand-wheels i9, one of which is pro- I vided with a firing key 20, are operatively connected to the shaft by a shaft 2| and bevel gears by which the telescope maybe setwin accordance with the selected roll of the ship as will I I hereinafter be described in detail.

A second auxiliary telescope '22 is mounted'by I means of shafts 23 in bearings 24 at the. upper ends of standards 25, attached to the ship athwartships, so that the movement of the telescope is in the plane of the pitch of the ship. One of the shafts23 carries at its free end a gear. sector 25 engaging -a worm-21. on a shaft 28 provided at one endwith coupled hand-wheels 23.

The roll and pitch converter l2 includes'apedestal 30 attached to the ship and carrying a rotatable annular table 3|, the periphery of which is provided withgear teeth engaged by a gear32 on the end of shafting ID, wherebythe table 3| maybe trained in accordance with the-training movement of the director Mounted upon the table 3| is a pair of standards 33 provided with bearings for shafts 34 which support a ring 35, which in turn is provided with bearings 36 for receiving shafts 31 disposed at right angles to the shafts 34 on which the ring issupported. The shafts 3'! serve to supports. plate 38 to which a rod 39 is attached to extend perpendicularly to the upper face of the plate.

The rod extends through aslotted member 40 forming part of a bail 4| one end of which is supported in a bearing 42 on the end ofa standard 43 attached to the ship. The other end of the bail is connected to the shaft H and is supported in the bearing 42 of another standard 43 likewise attached to the ship. Thestandards [8 on which the telescope I6 is supported and the standards 43 on which the bail 4| is mounted, lie in a plane which is perpendicular to the deck of the ship and parallel to the fore and aft line of the ship. The standards 33 which serve to support the ring 35 on the table 3| are arranged to lie in the plane of the standards 43 when therelative bearing of the target is 90 or 270 with respect to the fore and aft line, this being the condition shown in the drawing.

In addition to extending through the slotted member 40 forming a part of bail 4|, the rod39 also passes through a similar slotted member 44 forming a part of a bail 45 the ends of which are plane of the standard 4? and the bail 4'5'is athwartships. Anextended endof bail 45 carriesagear sector 49 engaging a worm 50 attached to the end of shaft 28, leading from the handwheels 29. I I I I As previously stated, the purpose of the roll and pitchconverter I3 is to-convert the selected-roll of theshipiand it yarying pitch into components of level .andcross level. The inputs to the roll and I pitch converter are the selected value of roll which is. introduced by the shaft I1. and the bail 4| and the varying values of pitch whichare introduced by the'shaft 28;and thebail 45-.

' .The output of level of the rolland .pitchconverter istaken off bymeans of a gear'sector 5| attached to one of the shafts 34' and engaging .a

pmionsz on shafting 53 which extends to one, side I 54' of a differential 54. The shafting' 53' will in its fore and aft line, so that the planeof movement I The gear sector .55 engages a pinion 5.6 on shafting 5?, it being understood that in practice ,an

practice be similarly arranged and, for the same purpose'as described in connection with shafting N.

The cross leveloutput of the roll and pitch converteristaken off by means of an arcuate gear sector55, attached to the plate 38 at right angles to the shafts '3'! by which the plate is supported.

arrangement similar to .that referred to in connection with shafting ID will be employed.

The other'side 54 of the differential .54 isconnectedzby a shaft.58 to a device indicated generally by '59, known as a cross level computer. An example of'such a computer is shown in United I sued November 28, 1933; for Fire controlsystem.

For this reason andbecause the particular form of cross level computer which may be employed forms no part of the present invention, this device will not be described in detail. It is .suflicient to state that the cross level output of the roll and pitch converter is transmitted by the shafting.5'| to the. cross levelcomputer, since this quantity is one .of the factors .upon which ,the Computation f t requ red cross level correction depends. Another factor upon which the ,correction depends is lateral or sight deflection which isintroduced by a crank ED. Another factor entering into the determination of the correction is sight depression, whichis the angle .by which the elevation of the gun relative to the horizontal exceeds that of the line of sight to take care of .the trajectory due to range. This factor is introduced by a crank 6|.

Theshaft 58 is operable by the cross level computer 59, in accordance with the required correction in elevation of the gun for the selected cross level corrected forpitch, and transmits this correction to the above referred to side 54" of the difierential 54. The center 54" of the differentia s connected by a shaft '62 to one side 53' of a. differential 63, the center 63' of which is attached to shafting 34 which is operatively connected to the crank.6|. The other side 63" of differential .33 is connected by a shaft 65 to a suitable electrical transmitter 66, the conductors 61 of whichlead to suitable receiving instruments at the guns, these devices being omitted in the interests of simplicity.

A vshaft 68 is operatively connected to the shafting Ill and to the center 69" of a diiferential 69, one side 69 of which is connected .to a e i i which i driven from the cross level computer to represent the sight, deflection corrected in accordance with the cross level output of the roll and pitch converter. The second side 69" of the differential 69 is connected by shaft H to an electrical transmitter 12 from which conductors 13 extend to suitable indicators at the guns.

In the operation of the apparatus described above, the operator of the director I will maintain its telescope 1 on the target in train by suitable manipulation of the hand-wheels 8 which will, through shafting l3 and pinion I5 cause the table 4 to turn in accordance with the relative bearing of the target. The movement thus imparted to the table 4 will, through shafting l and pinion 32, correspondingly position the table 3! of the roll and pitch converter l2.

The operator of the telescope It will by means of the hand-wheels 19 set the telescope with respect to the ship in accordance with the point in the roll of the ship which has been selected by him as the value of the roll at which the guns will be fired. The adjustment of the telescope by the operator will, through the shaft I! correspondingly adjust the bail 4| with respect to a plane perpendicular to the ship and containing the standards 43 upon which the bail is supported.

Simultaneously with the operations described above, an operator at telescope 22 will by suitable manipulation of the hand-Wheels 29 maintain the telescope on a distant object, such as the horizon, through the shaft 28, worm 2! and gear sector 26, so that the relative movement between the telescope and the ship will be in accordance with the pitch of the ship. This movement will, through worm 50 and gear sector 49, correspondingly' displace the bail 45.

The selected value of roll as measured by the setting of the telescope I6 is converted into selected level and selected cross level by the roll and pitch converter l2. Assuming zero pitch, the values of the selected level and selected cross level for any given value of roll depend upon the bearing angle of the target, that is, the train position of the table 3| and the parts carried thereby. The approximate value of the selected level will be the selected value of roll times the sine of the bearing angle; and the approximate value of the selected cross level will be the selected value of roll times the cosine of the bearing angle. For the purpose of illustration, the bearing angle shown in the drawing is 90 or 270 depending on whether the aspect is off the starboard or port side. Therefore in this particular relative bearing of the target the selected level is equal to the selected value of roll and the selected cross level is zero.

Assuming the relative bearing of the target to be something other than 90 or 270, and 0 or 180, the movement of the telescope I6 through. the selected value of roll will, through the bail 4| operate the rod 39 to tilt the plate 38 about both the axes 3l-3'l and 3434, the latter component being effected through the movement of the ring 35. The component of movement of the plate 38 about the axis 3l3l results in the ac tuation of the pinion B, and the component of movement of the plate'38 about the axis 34--3 t results in an actuation of the pinion 52. The output from the pinion 52 is the selected level for the existing relative target bearing and is transmitted through the shafting 53 to the difierential 54, as above described. Likewise, the output of the pinion 56 is the selected cross level for the existing relative target bearing and is transmit- 6 ted by the shafting 51 to the cross level computer 59, as above described.

The operator of the telescope 22 continuously measures the angle of pitch as he maintains his telescope on the horizon or other distant object, and this pitch is continuously effective to modify the selected level and cross level outputs of the shafts 53 and 57. This operation results in the movement of the bail 35, as above described. Just as the movement of the bail 4| is converted into level and cross level so the movement of the bail 45 is converted into level and cross level by the converter I2. In other words, the movement of the rod 39 resulting from the movement of the bail 45 causes angular movement of the plate 33 about the axes 3l3| and 31l34, the extent of movement about the respective axes depending on the relative bearing of the target, that is, the relative train position of the table 3|. It will be understood that the displacement of the plate 38 about the axis 34-34 is approximately equal to the product of the selected angle of roll and the sine of the bearing angle modified by the product of the angle of pitch and the cosine of the bearing angle; and that the displacement of the plate 38 about the axis 31-31 is approximately equal to the product of the selected angle of roll and the cosine of the bearing angle modified by the product of pitch and the sine of the bearing angle. In other words the output of the shaft 53 may be expressed by the approximate equation R sin bearing angle-l-P cos bearing angle and the output of the shaft 57 may be expressed by the approximate equation R cos bearing angle-i-P sin bearing angle It being the selected value of roll and P the varying value of pitch.

The first terms of these two equations constitute the selected level and cross level resulting from the setting of the telescope It, as above explained, while the second terms of the equations constitute the correction or modification of these selected level and cross level values by reason of the continuously changing values of pitch, that is to say, thevalue of roll is set or fixed and is not thereafter changed while the Value of pitch is a live value continually following the angular movement of the deck of the ship. I-Iaving selected a value of roll the operator of the telescope l6 thereafter merely observes when his telescope rolls on the horizon or other fixed object.

The values of sight deflection and sight depression are modified by the setting of the telescope E6 in accordance with the selected angle of roll and so long as that selected angle of roll is unchanged, the values of sight deflection and sight depression transmitted to the gun are not thereafter modified by reason of the roll of the ship. The pitch of the ship is, however, con tinuously converted into values of level and cross level, the latter of which is continuously used in the cross level computer to generate corrections in sight deflection and sight depression, which are transmitted to the transmitters 6S and 72 for transmission to the guns, as previously described.

The required inputs of sight deflection and sight depression will be applied to the computer by means of handles 69 and 6| respectively. The computer will determine and impart to theoutput shaft 58, the correction in elevation due to the cross level factor which is put into the computer'bythe shaft and the otherfactorsupon which this correction depends. .Aspreviously explained, the level component determined by the roll and pitch converter is transmitted to the side 54 of the differential 54. The elevation correction just referred to will be applied to the othersideid" of the. differential wherein it will be algebraically combined with the level input at the center 54' of the difierential which, by means of shaft 62, is connected to the side 63 of differential 63. The center 63 of this differential will receive from the shaft 64 the value of sightdepression, so that the latter quantity will be combined with the quantity represented by shaft-62 leading fromthe difierential 54 in which the elevation correction for cross levelhas been combined with .the component of level. Theoutput of the differential 63 will be the gun elevation with respect to the deck of the ship and-which, by means of-the transmitter 65 and conductor 61, will be transmitted to the guns in order that they may be properly aimed in elevation.

The target bearing determined by the director I will be transmitted through shaft 68 to the center 69 .of the differential 69 wherein it will be combined with the sight deflection corrected .for cross level which is transmitted by the shaft Hi to the side 69 of the differential 69. The resulting movement of the side 69" of the differential will represent the train which must be given to the guns in-order that they maybe properlyaimed, this value being transmitted to the guns by the transmitter 12 and conductor 13.

The firing keys 9 atithe director I and '20 at the telescope l6, are connected in series in the firing circuit. While the operator at the director will keep his key in circuit closing condition when his telescope l is upon the target in train, the firing circuit will not be established until the operator at the telescope l6 operates his firing key when the roll ofthe ship brings a distant object, such as the horizon, into coincidence with the horizontal cross wire of this telescope. At this instant the values of gun elevation and gun train transmitted to the guns correspond to those determined by the existing values of the relative hearing of the target, the selected roll of the ship, the pitch'of the ship, the sight deflection and the sight depression. In other words, the guns are thenproperly aimed in view of the factors upon which their aiming depends.

When the roll of the ship differs from that selected for the firing of the guns, the variations of gun train from the value corresponding to that at the selected point in the roll will be materially reduced from what they would be in systems of the character referred to in the introductory portions of this specification. This condition obtains at all target bearings other than athwartships. under which conditions the variations in train would be due entirely to the pitch of the ship. The variations in elevation of the guns are greater at bearings other than athwartshps than in other systems, but in the case of gunsaimed fore or aft they camiot exceed the pitch of the ship.

While in the embodiment of the invention disclosed herein manually operated means have been shown for determining the pitch of the ship and thepoint in its roll at which firing of the guns shall take place and for transmitting these quantities to the roll and pitch converter, the invention comprehends the'employment of 'mechanism for performing these functions automatically subject .to suitable. adjustment of the mechanism in accordance with the desired point in the roll at which firing'shall take place.

It will also be understood that'other embodiments of the invention and various changes in structural details may be made without departing from-theprinciple of the invention as defined in the appended claims.

What is claimed is:

1. 'Inapparatus for compensating for errors in the aiming of a gun due to cross level .of a ship on which the gunis mounted, the combinationof a device settable in accordance with aselected value of the roll of the ship, means for continuously determining the pitch of the ship, .means for continuously determining the relative bearing of a target, means under the control of said device and bothsaid meansfor converting the selected value of the roll and the continuously determined pitch into components of level and cross level for the relative bearing of the target, mechanism operable inpart in accordance with the value of the cross level componentfor computing the .correction in the aim of the gun to compensate-for errors due to cross level, means for transmitting the correction to the gun and means associated with said device whereby the gun may be fired when the roll of theship corresponds to that 'for which-the device'has been set.

2. In apparatus for compensating for errorsin the aiming of a gun due to cross level of aship on which the gunis mounted, the combinationof a device settable in accordance with a selected value of the roll of the ship, means for continu-.- ously determining the pitch of the ship-means for continuously determining the relative bearing of a target, means under the control of said device and both said means for converting the selected value of the roll and the continuously determined pitch-into components of level and .cross level for the-relative bearing of the target, mechanism operable in part in accordance with the value of the cross level component for computing the corrections in the aim of the gun both Sin train and elevation 'to compensate for errors dueto cross level, means for transmitting the corrections to the gun and means associated with said device whereby the gun may be firedwhen the roll of the ship corresponds to that for which the device has been set.

3. In apparatus for converting angular movements of a body in a pair ofplanes bearing'a'fixed relation to each other into components representing angular movements of the body in'a second pair of planes bearing a fixed relation to each other and a variable relation to the first named pair of planes, the combination of a memberadjustable in accordance with the angular movement in one of said first named planes, 2. second member adjustable in accordance with the angular movement in the other of said first named planes, a device adjustable in accordance with the variable relation between the first and second named pairs of planes, an element mounted on said device for movement about an axis, .asec- 0nd element mounted on the first element "for movement about an axis bearing a relation to'said first axis corresponding to the fixed relatiom'betweenthe planes in which the components ofangular movements lie and a part attached to said second element and co-acting with said members for displacing said elements in accordance with said components of angular movement.

4. In apparatus for compensating'forerrorsiin the aiming of a gun due to roll and pitch of a ship on which the gun is mounted, the combination of means adjustable in accordance with a selected value of the roll of the ship, means operable in accordance with the pitch of the ship, an element mounted for movement about an axis bearing a fixed relation to the ship and operatively connected to the first named means, a second element mounted for movement about an axis bearing a fixed relation to the ship and operatively connected to the second means, a device settable inaccordance with the bearing of a target, a member mounted on the device for movement about an axis bearing a fixed relation to the device, a second member mounted on the first member for movement about an axis bearing a fixed relation to the first member, a part attached to one of the members and coacting with the elements for displacement thereby, mechanism for determining the correction required to compensate for the error in the aiming of the gun, an operating connection between the other of the members and the mechanism, means for actuating said mechanism in accordance with other factors upon which the required correction depends, means operable by the mechanism in accordance with the determined. correction and means actuated by the last named means for transmitting the correction to the gun.

5. In an apparatus for compensating for errors in the aiming of a gun due to roll and pitch of a ship on which the gun is mounted, the combination of means adjustable in accordance With a selected value of the roll of the ship, means operable in accordance with the pitch of the ship, an element mounted for movement about an axis bearing a fixed relation to the ship and operatively connected to the first named means, a second element mounted for movement about an axis bearing a fixed relation to the ship and to the first named axis and operatively connected to the second means, a device settable in accordance with the bearing of a target, a member mounted on the device for movement about an axis bearing a fixed relation to the device, a second member mounted on the first member for movement about an axis bearing a fixed relation to the first member and a relation to the axis of the first member corresponding to the relation between the axes of the first and second elements, a part attached to one of the members and co-acting with the elements for displacement thereby,

mechanism for determining the correction required to compensate for the error in the aiming of the gun, an operating connection between the other of the members and the mechanism, means for actuating said mechanism in accordance with other factors upon which the required correction depends, means operable by the mechanism in accordance with the determined correction and means actuated by the last named means for transmitting the correction to the gun.

6. A device of the class described, comprising a first supporting member rotatable about a first axis, a second supporting member carried by the said first supporting member to be rotatable about a second axis normal to and intersecting the first mentioned axis, a member carried by said second supporting member to be rotatable about a third axis normal to the second axis and intersecting both the other said axes, a first slotted bail rotatable about a fourth axis normal to the first axis, a second slotted bail rotatable about an axis normal to the first axis and having a known relation to the fourth axis, a rod carried by said member extending through the slots in both said bails, means for relatively positioning said first bail in accordance with a selected point in a movement in one plane, means for moving said second bail in accordance with movement in a second plane having a known relation to the first said plane, means for movin said first supporting member to correspond to a position in azimuth, and means responsive to the resulting position of the member for positioning a pair of elements to represent the angular positions of said member about the second and third axis respectively.

CORA BUCK WILLARD. Eazecutrz'a: of the Estate of Waldo W. Willard,

Deceased.

RAYMOND E. CROOKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,829,181 Bates Oct. 27, 1931 1,985,756 Wittkuhns Dec. 25, 1934 1,937,336 Ford et a1 Nov. 28, 1933 1,891,397 Watson Dec. 20, 1932 1,733,531 Dugan Oct. 29, 1929 

